This invention is directed to transesophageal echocardiography (TEE) probes used for imaging human organs, particularly the heart. TEE probes are well known in the art and comprise an ultrasonic transducer mounted at the end of a semi-flexible endoscope. The endoscope typically has an articulation section at its distal end that allows the operator to rotate or move the distal end of the endoscope such that the ultrasonic transducer is optimally positioned for imaging the relevant organ. Movement of the articulation section is effected in a controlled manner through controls disposed on a handle located on the proximal end of the endoscope. The semi-flexible nature of the endoscope enables physicians or clinicians to introduce the ultrasonic transducer through the esophagus of a patient to a position where the heart or other relevant structure can be ultrasonically imaged.
Early prior TEE probes permitted only single plane scanning. Operators of these early TEE probes would rotate or move the probe back and forth such that the beam of the ultrasonic transducer would scan over a given scan plane. Although this generation of TEE probe could provide the operator with a single plane scan of a particular organ of interest, it was unable to provide a multi-plane scan. Subsequent TEE probes used two transducers to permit bi-plane scanning in two fixed orientations.
Prior TEE probes were subsequently improved to permit ultrasonic scanning in freely selectable multiple scan planes. This multi-plane scanning was accomplished by mechanically rotating the ultrasonic transducer of the TEE probe from the proximal end of the probe. Mechanical rotation of the ultrasonic transducer was accomplished with a mechanical linkage that extended from the proximal end of the TEE probe to the ultrasonic transducer located at the distal end of the probe. The types of mechanical linkages used in these prior devices are well known in the art, and included the use of either a push/pull wire or a flexible axle. Operators of these prior TEE probes could manipulate the mechanical linkage, and thereby also the scan plane of the ultrasonic transducer, through a handle located at the proximal end of the TEE probe. The handle would use a mechanical transfer mechanism (for example, a mechanical wheel) or motor to manipulate the mechanical linkage of the TEE probe, and thereby provide a multi-plane ultrasonic scan of the organ of interest.
However, the use of mechanical linkages in prior TEE probes limited the accuracy of the scan-plane angle that was measured and indicated at the handle of the probe. This was due primarily to the mechanical hysteresis and spring action effects that resulted from using a mechanical linkage to rotate the ultrasonic transducer. Further, the mechanical nature of the linkages made them vulnerable to failure and represented a negative contribution to the reliability of prior TEE probes. In short, the detrimental effect on scan-plane measurement accuracy associated with using mechanical linkages in TEE probes, as well as decreased reliability, was an undesired characteristic and limitation of prior TEE probes.
Therefore, there is a need for a TEE probe that addresses the prior problems and limitations associated with using a mechanical linkage to rotate a transducer for obtaining multi-plane ultrasonic scans of internal organs.
In a preferred embodiment of the invention, a transesophageal ultrasound probe allowing for scan-plane rotation includes an endoscope with a probe head connected to a distal end of the endoscope. A transducer is secured to the probe head, a transfer mechanism is connected to the transducer, and a motor at the distal end of the endoscope is connected to the transfer mechanism. An electrical wire is connected to the motor and extends to the proximal end of the transesophageal ultrasound probe. The configuration of the motor, the transfer mechanism, and the transducer may be changed in a number of ways to achieve varying performance characteristics. Preferably, the motor, the transfer mechanism, and the transducer are all disposed within the probe head.
In an alternative embodiment, a transesophageal ultrasound probe allowing for scan-plane rotation includes an endoscope with a probe head connected to a distal end of the endoscope. A transducer is secured within the interior of the probe head. Further, a transfer mechanism is secured within the interior of the probe heat and connected to the transducer. Also, a motor is secured within the interior of the probe head and connected to the transfer mechanism. Finally, an electrical wire is connected to the motor and extends to the proximal end of the transesophageal ultrasound probe.
The preferred embodiment has a number of advantages. In particular, the present invention uses a motor in the distal tip of the transesophageal ultrasound probe to allow a clinician to alter the scan-plane of the transducer at will by rotating the transducer around an axis perpendicular to the transducer surface through the use of a transfer mechanism connected to the transducer. The motor is powered through an electrical wire, thereby eliminating the need for the mechanical linkages of prior devices. Other features and advantages of the invention will became apparent from the description that follows.